Pneumatically-operated piano.



C. GULBRANSON. PNEUMATICALLY OPERATED PIANO.

APPLICATION FILED SEPT. 1, I91 I.

Patented Nov. 9, 1915.

Wop/MM M w M IIITTlE coLuMmA PLANOORAPH co mm-rm u c UNITED STATESPATENT OFFICE.

CHRISTIAN GULBRANSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO GULBR-ANSEN-DICKINSON COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

PNEUMATICALLY-OPERATED PIANO.

Application filed September 1, 1911.

To all whom it may concern:

Be it known that I, CHRISTIAN GULBRAN- SON, a citizen of the UnitedStates, residing at Chicago, in the county of Cook and State ofIllinois, have invented a certain new and useful Improvement inPneumatically-Operated Pianos, of which the following is a full, clear,concise, and exact description, reference being had to the accompanyingdrawings, forming a part of this specification.

My invention relates to pneumatically operated pianos and is concernedwith the contents of the roller box. It is well known that in pneumaticpiano actions, a roller box is disposed in front of the hammers inalinement with an opening in the front panel of the piano casing. Thisbox contains the tracker board and the means for passing a music stripor sheet from one roll, over the tracker board, to another roll.

My invention is directed toward an im proved arrangement for guiding themusic strip, of paper, so that it may always bear the proper relation tothe tracker and so that it will bear such a relation that the paper willnot tend to stick to vthe face of the tracker, either because of itscomposition or because of the difference in pressure on the two sideswhich is created by action of the pneumatic mechanism. It has been foundin practice that many grades of paper tend to stick to the face of thetracker, particularly in warm weather or in a warm room, and this isascribed to the composition of the paper or to its lack of porosity. Thepaper may carry adhesive particles which produce this undesirable resultor it may be so firm in its composition that the pneumatic potentialproduced by the bellows draws it firmly to the face of the trackerthrough which the suction is applied. The tendency for the music sheetto stick retards the action of the roller driving mechanism and the dragis often su'liicient to seriously mar the tempo of the music.

It is the object of my invention to avoid this difficulty and I do thisby guiding the music sheet in a certain position relative to the face ofthe tracker, which position is maintained regardless of the extent towhich the roll becomes wound or unwound, so that the area of contactbetween the music strip and the tracker is limited as far as possibleSpecification of Letters Patent.

Patented Nov. 9, 1915.

Serial No. 647,158.

to the zone in which the tracker openings are provided. To this end, Iprovide a guiding roller, parallel to the tracker, and I have found itparticularly desirable to mount this roller on the departing side of thetracker. There is also an advantage in mounting such a roller on theapproaching side of the tracker and rollers may be provided in bothplaces if desired. These rollers are adjustable in a manner to bedescribed in order that the positioning of the music sheet may beregulated to a degree.

My invention is embodied in the structure illustrated in theaccompanying drawings, in which Figure 1 is a front elevational view ofthe roller box with its contents and some of the directly associatedparts; Fig. 2 is a cross sectional view taken on the plane of the line2-2 of Fig. 1, looking in the direction indicated by the arrows anddrawn on a larger scale; Fig. 3 is a view of one of the parts formounting the roller, drawn on a still larger scale; and Fig. 4: isanother view of this mounting piece, parts being shown in section tofurther illustrate the construction.

The roller box is illustrated at 5 and is divided into two compartmentseach for the reception of a roll. In each compartment there are deadbearings 6, 6, extending inwardly from one of the side pieces, and thesebearings are adapted for the reception of the rollers 7, 7. Livespindles 8, 8 are mounted in bearings 9, 9 and these spindles areprovided with chain and clutch mechanism 10, 10 for driving either ofthem. \Vhen the instrument is playing, it is usual to make the upperroller the feeding one and the lower roller the receiving one. The chainand clutch mechanism is not concerned with this invention, so it isshown more or less diagrammatically.

The tracker piece 11 is mounted parallel to the roller axes, at thefront of the roller box, and this tracker piece is provided with theusual series of openings 12, 12 which, by means of suitable piping 13,13, are connected to the pneumatic action members. The face of thetracker piece is convex, traced by a line moving parallel to the axes ofthe rollers, and the music sheet a is run from one roller to the otherin the manner clearly illustrated in Fig. 2.

On each of the side pieces of the roller box, just belowthe trackerpiece, a support.- ing block 14 is pivotally mounted by means of a screw15 near the bottom thereof. This supporting block, which is shown indetail in Figs. 3 and a, may be swung about the pivot member 15 and maybe clamped inany v adjusted position by means of a screw 16 passingthrough an arcual slot 17 in the block. A washer 18 may intervenebetween the head of the screw and the block in-order that the latter maynot be injured. The two supporting blocks register with each other,longitudinally of the ,roller box, and between them, at the top thereof,the auxiliary roller 19 is mounted, this roller having the trunnions 20,20 which rest in suitable hearing openings in the blocks. The blocks areso adjusted that the roller 19, over which the music sheet is thus madeto pass, holds the music sheet away from the face of the tracker exceptfor that part at which it controls the tracker openings. Thus, the musicsheet leaves the tracker boardat a tangent, and gradually and not onlydoes not pass over an edge in leaving, but is confined to a limited areaon the face of the tracker. Furthermore, regardless of the angle atwhich the sheet approaches the receiving roll, depending upon the extentto which the roller has been wound, the sheet will always leave the faceof the tracker at the same angle. The same sort of an arrangement maybeprovided above the tracker piece and, for convenience, I have appliedthe same reference characters to the structure which I have shown inthat position.

Here, regardless of the angle at whichthe paper strip leaves the feedingroll, it will always approach the face of the tracker at the sameangle,.will be-confined to a limited area, and will approach it at atangent rather than over an edge. It is apparent that any adjustment maybe made by loosen- 7 ing the screws 16, swinging the blocks 14, andagain tightening the screws 16 so that the paper strip may bear anydesired relaion to the face of the tracker. It is to be understood thatthe paper travels in a down ward direction while the instrument is playing and that, in the rewinding operation,

there is no suction applied to the inner face of the paper so the dragwhich has. been referred to will not occur. If but one roller is to beemployed, I believe it preferable that this roller be mounted uponthepower side, that is, if the paper travels in a clownward direction thelower roll is the power roll and the roller 19 is provided under the"tracker.

I claim as new and desire to secure by Letters Patent:

1. In a pneumatically operated piano, a supporting frame, a trackermember mounted on said frame, a music roll on each side of saidtracker,an elongated guiding member extending parallel to the tracker and over.which the music strip may pass, said guiding member being on the sameside of said music strip as said tracker, swinging 'arms carrying saidguiding member, and means for securing said arms in any adjustedposition.

2. In a pneumatically operated piano, a supporting frame, a trackermember with a convex surface in which ducts lead mounted on said frame,a music roll on each side of said tracker, and an adjustably mountedelongated guiding member extending parallel to the tracker and overwhich the music strip may pass, said guiding member being on the sameside of said music strip as said tracker, the guiding surface of theguiding member lying in substantially the same plane as the edges ofsaid ducts.

3. In a pneumatically operated piano, a roller box, a tracker mountedwithin said roller box and having a series of openings therein, rollsadaptedto carry a perforated music sheet over said tracker, theperforations in said sheet being adapted to cooperate with saidopenings, and a guiding roller mounted above and below said trackerboard on the same side of the music sheet with the tracker to engage themusic sheetto prevent the music sheet from sticking to the said trackerboard.

4. In a device of the class described, a'

CHRISTIAN e LBRANsoN.

Witnesses:

A. G. GULBRANSON, ARTHUR H. BOETTGHER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

.Washington, D. C. V

